Conventional television systems utilize an interlaced scanning method to transmit pictures, each consisting of two fields. In order to conserve bandwidth, maximize vertical resolution, and reduce large area flicker, interlaced scanning provides an increased field rate by scanning alternate line positions in alternate fields. The resulting display at the receiver, however, can exhibit artifacts such as visibility of the scanning lines, line flicker on vertical detail, line crawl or pairing, breakup or serrating of moving edges, and loss of vertical resolution.
A sequential scanning method results in a retrace of the same lines of both fields every vertical sweep. By converting the interlaced signal into a sequentially scanned display at the receiver, a substantial reduction of the artifacts caused by interlaced scanning will be achieved.